Public health officials in Yolo County confirmed Wednesday that a resident there who recently returned from international travel contracted the Zika virus, the latest of several confirmed cases in California.

The person, whose identity and gender were not released, had recently traveled to a country in the Caribbean or Central or South America and contracted the virus, said Beth Gabor, a spokeswoman for the Northern California county.

She said the person is not pregnant and has a "mild case." The person is not under any travel restrictions.

Zika is a mosquito-borne illness that until 2015 occurred only in Africa, Southeast Asia and the Pacific Islands.

After an outbreak in Brazil last year, the virus has spread to 20 countries throughout the Americas.

Transmission occurs when a mosquito bites a person infected with the Zika virus, then bites another person. The virus is not contagious.

Symptoms of Zika virus include rashes, joint pain, fever and red eyes. There is no vaccine.

Since 2013, there have been six confirmed cases of Zika in California, officials with the state Department of Public Health said last week.

Some suspect the virus is tied to a spike in birth defects in Brazil. Last year, thousands of babies were born with microcephaly, in which a child's head is abnormally small. Health officials in some Latin American counties have told women to hold off on becoming pregnant.

The Centers for Disease Control and Prevention has recommended that pregnant women in any trimester should refrain from traveling to regions where the Zika virus is active.

"If you are pregnant, consider postponing your trip," said Ron Chapman, the health officer of Yolo County. "Pregnant women who have recently traveled to an area with Zika should talk to a healthcare provider about their travel even if they don’t feel sick."

As of Feb. 3, 35 cases of Zika had been reported in the U.S., all associated with international travel.